feat: make delete word in promp work more like bash

Now when you delete a word in a promp it will work more like how it
works in bash. If the text dose not end in a letter then the last word
and all of the tailing special characters will be deleted. If the text
dose end in a letter then only the last word will be deleted leaving the
special characters that are before the last word.

Examples:

| Before             | After       |
| -------------------| ----------- |
| `some word`        | `some `     |
| `some     word`    | `some     ` |
| `some word       ` | `some `     |

lua/ivy/prompt.lua

@@ -1,6 +1,23 @@
 -- The prefix that will be before the search text for the user
 local prompt_prefix = ">> "
 
+-- Gets the suffix to delete from some text biased on what happens in a bash
+-- prompt. If the text dose not end in a letter then the last word and all of
+-- the tailing special characters will be returned. If the text dose end in a
+-- letter then only the last word will be returned leaving the special
+-- characters that are before the last word. For example
+--
+-- `some word` -> `some `
+-- `some     word` -> `some     `
+-- `some word       ` -> `some `
+local function get_delete_suffix(text)
+  if text:match "([A-Za-z]+)$" == nil then
+    return text:match "([A-Za-z]+[^A-Za-z]+)$"
+  end
+
+  return text:match "([A-Za-z]+)$"
+end
+
 local prompt = {}
 
 prompt.suffix = ""
@@ -9,6 +26,7 @@ prompt.value = ""
 prompt.text = function()
   return prompt.value .. prompt.suffix
 end
+
 prompt.update = function()
   vim.api.nvim_echo({
     { prompt_prefix, "None" },
@@ -32,9 +50,12 @@ prompt.input = function(char)
       prompt.suffix = prompt.suffix:sub(2, -1)
     end
   elseif char == "DELETE_WORD" then
-    prompt.value = prompt.value:match "(.*)%s+.*$"
-    if prompt.value == nil then
+    local suffix = get_delete_suffix(prompt.value)
+
+    if suffix == nil then
       prompt.value = ""
+    else
+      prompt.value = prompt.value:sub(1, #prompt.value - #suffix)
     end
   elseif char == "\\\\" then
     prompt.value = prompt.value .. "\\"

lua/ivy/prompt_test.lua

@@ -51,7 +51,7 @@ end)
 it("can delete a word", function(t)
   prompt.set "Ade Attwood"
   input { "DELETE_WORD" }
-  assert_prompt(t, "Ade")
+  assert_prompt(t, "Ade ")
 end)
 
 it("can delete a word in the middle", function(t)
@@ -59,3 +59,36 @@ it("can delete a word in the middle", function(t)
   input { "LEFT", "LEFT", "DELETE_WORD" }
   assert_prompt(t, "Ade  A")
 end)
+
+it("will delete the space and the word if the last word is single space", function(t)
+  prompt.set "some.thing "
+  input { "DELETE_WORD" }
+  assert_prompt(t, "some.")
+end)
+
+it("will only delete one word from path", function(t)
+  prompt.set "some/nested/path"
+  input { "DELETE_WORD" }
+  assert_prompt(t, "some/nested/")
+end)
+
+it("will delete tailing space", function(t)
+  prompt.set "word                 "
+  input { "DELETE_WORD" }
+  assert_prompt(t, "")
+end)
+
+it("will leave a random space", function(t)
+  prompt.set "some word       "
+  input { "DELETE_WORD" }
+  assert_prompt(t, "some ")
+end)
+
+local special_characters = { ".", "/", "^" }
+for _, char in ipairs(special_characters) do
+  it(string.format("will stop at a %s", char), function(t)
+    prompt.set(string.format("key%sValue", char))
+    input { "DELETE_WORD" }
+    assert_prompt(t, string.format("key%s", char))
+  end)
+end